Construction of Dynamic Model for Free Standing Spent Fuel Rack Under Seismic Excitations

2015 ◽  
Author(s):  
Shigehiko Kaneko ◽  
Hironao Shirai
Keyword(s):  
Dynamic Model ◽  
Nuclear Power ◽  
Scale Model ◽  
Spent Fuel ◽  
Seismic Excitations ◽  
Power Station ◽  
Free Standing ◽  
Method Of Calculation ◽  
Gap Flow ◽  
Real Size

Free standing rack designed for storing spent fuel at nuclear power station has an advantage to earthquake excitations because both fluid force and friction force can reduce the movement of a rack. However, there are various motions of FS rack such as parallel, rotational and rocking which should be taken into consideration when it is subjected to earthquake excitations. Therefore, the motion of FS rack must be precisely figured out in order to apply FS rack design concept. In this research, to investigate the motion of FS rack, 2-dimensional dynamic model considering pressure loss of gap flow was constructed. In addition, an experiment with a 1/16 scale model was conducted to validate the dynamic model. From numerical results based on the proposed dynamic model, some important features for the design of FS rack were found. Finally, case studies by real size free standing rack under the excitation of actually observed earthquake wave like The Great East Japan earthquake and The Niigata-ken Chuetsu-Oki earthquake were conducted based on the proposed method of calculation.

The Sliding and Overturning Analysis of a Free-Standing Cask under Earthquake

2007 ◽  
Vol 120 ◽  
pp. 207-212 ◽  
Author(s):  
R.F. Shie ◽  
Kung Ting ◽  
J.S. Yu ◽  
C.T. Liu
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Computer Code ◽  
Storage Facility ◽  
Spent Fuel ◽  
Power Station ◽  
Free Standing ◽  
Safety Assurance ◽  
Maximum Earthquake ◽  
Interim Storage

A freestanding spent fuel interim storage facility is possible to be selected to house the spent fuel for ChinShan nuclear power station in a period of 5 to 50 years. The design specifications of the storage facility should provide adequate safety assurance under the event of a major earthquake. ANSYS/LS-DYNA computer code is employed in this study to simulate the dynamic behavior of the cask under extremely seismic loading, the criterion which is used to judge whether freestanding cask will slide or overturn is thus established. A cylindrical cask is used as an object which subjected to safety shutdown earthquake of support pad of ChinShan nuclear power station. The cylindrical cask will slide but will not overturn is obtained under maximum earthquake loading.

Seismic Design of Free Standing Racks in Japanese Nuclear Power Plants

2017 ◽  
Author(s):  
Yu Takaki ◽  
Katsuhiko Taniguchi ◽  
Junichi Kishimoto ◽  
Akihisa Iwasaki ◽  
Yoshitsugu Nekomoto ◽  
...  
Keyword(s):  
Seismic Design ◽  
Nuclear Power ◽  
Power Plants ◽  
Design Method ◽  
Seismic Resistance ◽  
Spent Fuel ◽  
Analysis Model ◽  
Free Standing ◽  
Scale Free ◽  
Seismic Design Method

The free standing racks are spent fuel storage racks with self-sustained structure without fixation to the pit floor or pit walls. If a free standing rack receives a force to move it due to an earthquake, the force acting on each member of the rack is reduced in compared to the floor-anchored racks owing to sliding of the free standing rack. Now it is planned to exchange the existing floor-anchored racks with the free standing racks to secure higher seismic resistance. In previous studies, efforts were made to establish a behavior analysis model that allows for evaluation of sliding and rocking behaviors of free standing racks and to make out a seismic design method based on an evaluation technique to evaluate, in a conservative manner, vibration test results of full-scale free standing racks. The free standing racks which consist of connected eight racks are designed with this seismic design method. It was confirmed that the free standing racks have enough seismic resistance by performing evaluation using the basic seismic motion and making an analysis on beyond the design event.

Thermal-Hydraulic Analysis of the Fort St. Vrain Modular Vault Dry Store System

1991 ◽  
Vol 113 (4) ◽  
pp. 522-529 ◽  
Author(s):  
S. M. Cho ◽  
A. H. Seltzer ◽  
M. Blackbourn
Keyword(s):  
Nuclear Power ◽  
Hydraulic Characteristics ◽  
Spent Fuel ◽  
Hydraulic Analysis ◽  
Power Station ◽  
Limit Values ◽  
Hydraulic Design ◽  
Loading And Unloading ◽  
Design Analyses ◽  
Thermal Hydraulic Analysis

A passive, natural thermosyphon, air-cooled modular vault dry store (MVDS) system is being constructed for the storage of nuclear spent fuel for the Fort St. Vrain (FSV) Nuclear Power Station. In support of this FSV-MVDS system, thermal-hydraulic design analyses have been performed. The objective of the analyses is to determine flow and temperature distributions within the system and thus to ensure that the maximum fuel element temperatures shall not exceed specified design limit values under various loading and unloading conditions. This paper presents the method of analysis and discusses the resulting thermal-hydraulic characteristics of the MVDS system.

Behavior of Full-Scale Model Cask Under 9m Drop Test and Simulation

2006 ◽  
Author(s):  
Kiminobu Hojo ◽  
Tadashi Kimura ◽  
Akio Kitada ◽  
Hiroshi Tamaki ◽  
Junich Kishimoto ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Nuclear Power ◽  
Simulation Method ◽  
Full Scale ◽  
Drop Test ◽  
Scale Model ◽  
Test Facility ◽  
Spent Fuel ◽  
Federal Institute

The nuclear spent fuel transport and storage cask is used for transport of the spent fuel from a nuclear power station to an intermediate storage facility. Leak tightness and subcriticality on transportation required from IAEA TS-R1 [1] have to be assured by a 9m drop test and its numerical simulation. This paper describes the drop test using a full-scale prototype test cask. The test was conducted by German Federal Institute for Materials Research and Testing (BAM) at their test facility in Horstwalde, Germany and comparison of the test result with the “MH1 (Mitsubishi Heavy Industries, Ltd.)” numerical simulation using LS-DYNA code. The drop orientations of the tests were slap down and vertical. From the drop test the following is demonstrated: • The leak rate of He gas after the drop tests satisfied the IAEA’s criteria. • The numerical simulation which modeled the cask body enabled dynamic response such as acceleration and strain of the cask body. This means the simulation method qualified the relation of dynamic response of the cask body and leakage behavior.

scholarly journals Finite Element Modeling and Analysis of Nonlinear Impact and Frictional Motion Responses Including Fluid—Structure Coupling Effects

1997 ◽  
Vol 4 (5-6) ◽  
pp. 311-325 ◽  
Author(s):  
Yong Zhao
Keyword(s):  
Finite Element ◽  
Nuclear Power ◽  
Time History ◽  
Spent Fuel ◽  
Free Standing ◽  
Surrounding Water ◽  
Fluid Structure ◽  
Modeling And Analysis ◽  
Motion Responses ◽  
Fuel Assemblies

A nonlinear three dimensional (3D) single rack model and a nonlinear 3D whole pool multi-rack model are developed for the spent fuel storage racks of a nuclear power plant (NPP) to determine impacts and frictional motion responses when subjected to 3D excitations from the supporting building floor. The submerged free standing rack system and surrounding water are coupled due to hydrodynamic fluid-structure interaction (FSI) using potential theory. The models developed have features that allow consideration of geometric and material nonlinearities including (1) the impacts of fuel assemblies to rack cells, a rack to adjacent racks or pool walls, and rack support legs to the pool floor; (2) the hydrodynamic coupling of fuel assemblies with their storing racks, and of a rack with adjacent racks, pool walls, and the pool floor; and (3) the dynamic motion behavior of rocking, twisting, and frictional sliding of rack modules. Using these models 3D nonlinear time history dynamic analyses are performed per the U.S. Nuclear Regulatory Commission (USNRC) criteria. Since few such modeling, analyses, and results using both the 3D single and whole pool multiple rack models are available in the literature, this paper emphasizes description of modeling and analysis techniques using the SOLVIA general purpose nonlinear finite element code. Typical response results with different Coulomb friction coefficients are presented and discussed.

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